package com.hmdp.service.impl;

import cn.hutool.core.bean.BeanUtil;
import com.baomidou.mybatisplus.core.conditions.query.QueryWrapper;
import com.hmdp.dto.Result;
import com.hmdp.dto.UserDTO;
import com.hmdp.entity.Follow;
import com.hmdp.entity.User;
import com.hmdp.mapper.FollowMapper;
import com.hmdp.service.IFollowService;
import com.baomidou.mybatisplus.extension.service.impl.ServiceImpl;
import com.hmdp.service.IUserService;
import com.hmdp.utils.UserHolder;
import org.springframework.data.redis.core.StringRedisTemplate;
import org.springframework.stereotype.Service;

import javax.annotation.Resource;
import java.util.Collections;
import java.util.List;
import java.util.Set;
import java.util.stream.Collectors;

/**
 * <p>
 *  服务实现类
 * </p>
 *
 * @author 虎哥
 * @since 2021-12-22
 */
@Service
public class FollowServiceImpl extends ServiceImpl<FollowMapper, Follow> implements IFollowService {
    @Resource
    private StringRedisTemplate stringRedisTemplate;
    @Resource
    private IUserService userService;
    @Override
    public Result follow(Long followUserId, Boolean isFollow) {
        //获取登录用户
        Long userId = UserHolder.getUser().getId();
        String key="follows:"+userId;
        //1.判断到底是关注还是取关
        if(isFollow){
            //2.关注，新增数据
            Follow follow = new Follow();
            follow.setUserId(userId);
            follow.setFollowUserId(followUserId);
            boolean isSuccess = save(follow);
            if(isSuccess){
                //把关注的用户id，放入redis的set集合
                stringRedisTemplate.opsForSet().add(key,followUserId.toString());
            }
        }else {
            //3.取关，删除
            boolean remove = remove(new QueryWrapper<Follow>()
                    .eq("user_id", userId).eq("follow_user_id", followUserId));
            //把关注的用户id从redis集合移除
            if(remove) {
                stringRedisTemplate.opsForSet().remove(key, followUserId.toString());
            }
        }

        //3.取关,删除
        return Result.ok();
    }

    @Override
    public Result isFollow(Long followUserId) {
        //获取登录用户
        Long userId = UserHolder.getUser().getId();
        //1.查询是否关注
        Integer count = query().eq("user_id", userId).eq("follow_user_id", followUserId).count();
        //2.判断

        return Result.ok(count>0);
    }

    @Override
    public Result followCommons(Long followUserId) {
        //获取登录用户
        Long userId = UserHolder.getUser().getId();
        String key="follows:"+userId;
        String key2="follows:"+followUserId;
        Set<String> intersect = stringRedisTemplate.opsForSet().intersect(key, key2);
        if(intersect==null||intersect.isEmpty()){
            //无交集
            return Result.ok(Collections.emptyList());
        }
        List<UserDTO> userDTOS = intersect.stream().map(obj -> {
            User user = userService.getById(obj);
            UserDTO userDTO = BeanUtil.copyProperties(user, UserDTO.class);
            return userDTO;
        }).collect(Collectors.toList());
        return Result.ok(userDTOS);
    }
}
